A kid-size 737-100

The finished kid-size 737 on a parking lot: blue fuselage, a red, orange and yellow tail, grey wings and engines, an open cabin and a black tow handle at the nose — The finished plane, with a tow handle at the nose.

One prompt at a time

It started with a prompt to Claude: "Scale a 737 so the cabin is 18" wide." The answer was a 737-800 almost 17 feet long, which wasn't going to fit anywhere. So I kept asking: what's the shortest 737, what if the cabin is 14", can the wings be shorter? Each answer narrowed it down.

737-800, cabin 18" widefirst try16′9″

737-100, cabin 18" wideshortest 73712′2″

737-100, cabin 14" widefirst PDF9′6″

6 ft versiontoo small to sit in6′

8 ft versionthe one that got built8′2″

Overall length of each version, in order. The last one fits the kids, a 12" cabin and a 6 ft wingspan.

The real requirements came out along the way:

Room for the kids sitting sled-style, each between the knees of the one behind. That set the 58"-long opening and a 12" minimum cabin width.
No more than 6 ft tip to tip. At true scale the wings would be 97", so they're built at 73% scale while the fuselage stays almost exactly true to the real plane, at about 1:11.5.
An open top. A seated child is taller than a scale fuselage, so the roof comes off over the cabin.
Two small furniture dollies instead of landing gear, bolted to a plywood floor. I changed these to simple casters in the end, with swivels on the front.

Getting the proportions right

Once there was a PDF, the work shifted to making it look like a 737 and not just a box with wings. I asked for a dimension on every edge so the parts would cut in proportion, then started questioning the shape:

The nose was too blunt. It became a carved foam cone with the tip 5" up and a rounded chin, traced from a grid on the plans.
The fin was too narrow and too upright. It was checked against Boeing's airport planning data for the 737-100 and redrawn with a longer root and more sweep. The horizontal tail grew to match.
The engines were too long once the wings were scaled down. They went from 18" to 14", still 4" across so they look right next to the fuselage.
A yoke for the front seat. A 6"-wide, ram's-horn yoke on a sliding dowel, with stop collars so it never gets close enough to pinch fingers.

Sheet 1 of the plans: top view of the kid-size 737 with every dimension in inches — Sheet 1, the top view. The plans also have the side view, cut patterns for the center box, nose cone, tail cone, wings, fin, engines and yoke, and a cut list.

Sheet 2 of the plans: side view showing heights from the ground, the dollies and stations along the fuselage — Sheet 2, the side view, with every station measured from the nose.

The cockpit

The last piece came from a separate conversation: a full-page, captain's-side 737 panel to print for the cockpit, with the autopilot panel, flight displays, engine gauges and gear lever. "No yoke," because the plane already has one.

Printable 737-style captain's instrument panel with autopilot controls, flight displays, engine gauges, flaps and landing gear lever — The printable cockpit panel, sized for one Letter landscape page.

A turnaround of the finished plane.

Build it yourself

Everything is in inches, and every edge is dimensioned. The plans call for ½" plywood sides, ¾" plywood for the bulkheads, floor and yoke, and 2" XPS foam board for the carved nose and tail cones. However, I used a light wood box for the fuselage, and then cardboard and paper for the rest, building out ribs for the nose and tail.

Cardboard ribs for the nose, taped together on the garage floor — Cardboard ribs for the nose.

The cardboard nose ribs wrapped in clear plastic — The nose ribs, wrapped in plastic.

The open fuselage box on casters, with the paper-covered nose cone beside it — The fuselage box on its casters, with the nose cone.

The tail section: a cardboard box frame with the fin and horizontal tail pieces edged in green tape — The tail section, fin and horizontal tail.

All the parts laid out before assembly: fuselage, nose and tail cones, fin, wings and engines — Every part, ready to assemble.

Plans (PDF, 9 sheets) Cockpit panel (PDF)

A homemade toy, not a certified product. Supervise kids, pad every edge, and lock the casters when it's parked.